Research On Hexahedral Mesh Matching Based On BaseComplex

Automatic generation of hexahedral meshes for complex geometries is still a challenging problem,the domain-decomposition based method is one of the promising methods for such problems.When generating the meshes if sub-components of a domain,it is often necessary to impose consistent mesh constraints on the interfaces between sub-components.The adoption of mesh matching algorithms can relax such constraints,and improve the efficiency and robustness of the mesh generation framework.A lot of work has been done on the mesh matching algorithm,but there are still some problems,mainly reflected in:(1)The algorithm does not consider the topology of the hexahedral mesh,resulting in many redundant iterative operations,which reduces the efficiency of the algorithm.(2)Neglecting the connection between vertex position and mesh quality makes the quality of output hexahedral mesh poor or even produces inverted elements.(3)The depth parameter given by the original algorithm makes the algorithm limited to the scene of the plane interfaces.Aiming at the problems existing in the current work,combined with the research on hexahedral mesh topology in recent years,this paper proposed an improved mesh matching algorithm based on base-complex.In order to expand the applicability of the algorithm,this paper also proposed also proposes a mesh matching algorithm for surface interfaces.The main contributions of this paper are as follows:1.To address problems 1 and 2 of the current algorithm mentioned above,a hexahedral mesh matching algorithm based on base-complex adapted to a planar interface is proposed.First,the mesh topology at the interface is simplified to obtain its base complex structure,and then the matching of the interface is performed on this base complex structure,and then the segment matching operation is used to achieve the matching of the mesh cells at the interface.Finally,to improve the mesh quality,an optimization algorithm is used to merge the mesh vertices on both sides of the interfaces.The experiments show that the algorithm can effectively reduce the number of topological operations and improve the efficiency of the algorithm while obtaining high-quality mesh.2.A hexahedral mesh matching algorithm adapted to the surface interface is proposed.To address problem 3 of the current algorithm mentioned above,the algorithm proposes a mesh grafting operation adapted to surfaces and a mesh localization operation that takes into account the depth and breadth directions.Finally,by combining the above two operations,the mesh matching algorithm based on the base complex structure is extended to the mesh matching problem adapted to the surface interface.Experiments show that the matching algorithm in this paper can effectively handle surfaces with feature constraints and multiple matching of models.